For the past eighteen months, the Greek artist who calls himself Stefanos has been hacking euros, sketching images of the economic crisis in Greece onto banknotes. ‘Over the last five years the economy has hatched violence and social decay,’ he told me. ‘I’m using a European document, that is in cross-border circulation, to bomb public property from the comfort of my home.’ The notes depict lynchings, people collapsing, mass hysteria. The project was kickstarted by news of a suicide. ‘I always use black ink ball-pen and draw human figures using headlines from the media, whenever violence or poverty is reported, I transfer the message on the medium.’ Stefanos scans the notes, posts the images on his website and then puts them back into circulation, messages in bottles that may wash up on the shores of northern Europe. ‘A currency should reflect the reality of the era it represents,’ he says.

In the 1970s Cildo Meireles stamped ‘Yankees Go Home’ onto dollar bills. Stefanos’s work is cautious by comparison. The Greeks queuing at cash machines might easily miss or misinterpret the tiny sketches. They will not strike fear into Eurocrats. There’s a degree of defeated weariness about the whole enterprise. There are images of the grim reaper but also designs that allude to Hitchcock’s Vertigo.

Stefanos’s day job is in a design consultancy. Many of his Greek clients export high-end food and beauty products to Western Europe and the US. There are big brands among his European clients. He apparently worked on the redesign of Piraeus Bank’s corporate identity. As he admits, his ‘bombs’ are thrown from relative comfort.

‘I didn’t vote for Syriza,’ he says, ‘but I do, to some extent, agree with some of their positions… The media is oppressive and misinforms. It would be wrong to talk about Syriza’s actions without considering our lenders’ position.’

He told me that the British Museum took two of his notes into their permanent collection; when I spoke to them they said the donation had been unsolicited, if welcome. ‘Banknotes will become as romanticised as vinyl or cassettes or Polaroids,’ Stefanos says. His notes at least have become collector’s items, worth far more than the values they supposedly represent.